1. Field of the Invention
The present invention relates to a semiconductor element testing carrier for holding a semiconductor element to be tested and, more particularly, to a semiconductor element testing carrier using a membrane contactor which is temporarily connected to terminals of the semiconductor element so as to provide tester signals to the semiconductor element during a test process.
The semiconductor element to be tested by being held in such a carrier may include a bare chip type semiconductor element, a ball grid array (BGA) type semiconductor element, a small outline package (SOP) type semiconductor element or a quad flat package (QFP) type semiconductor element.
As miniaturization, high speed and high densification are required for recent electronic circuits, attempts are made to form finer electrodes provided on a semiconductor element. When a test is performed on such a semiconductor element having fine electrodes, a contactor which can achieve a reliable electrical connection is required.
As for a contactor satisfying such a requirement, a membrane contactor has been suggested and use of the membrane contactor has being increasing. The membrane contactor is formed by a polyimide film with a conductive pattern provided thereon. Accordingly, a semiconductor element testing carrier using such a membrane contactor has been developed, especially for testing a bare chip type semiconductor element.
2. Description of the Related Art
In a conventional semiconductor element testing carrier using a membrane contactor, a semiconductor element to be tested is placed at a predetermined position of the membrane contactor, and thereafter, a pressing unit is placed on a back side of the semiconductor element which back side is opposite to the side being contacted by the membrane contactor so as to press the semiconductor element against the membrane contactor. That is, the conventional carrier has a three-stage arrangement such as the membrane contactor-the semiconductor element-the pressing unit arranged in that order from the bottom side.
FIG. 1 is a side view of the conventional semiconductor element testing carrier. The semiconductor element testing carrier 1 shown in FIG. 1 comprises a membrane contactor 3, a frame 4, a cap 5, a pressing unit 7, a fence 10 and a cushion member 11.
The membrane contactor 3 has tester pads (not shown in the figure) on a periphery thereof so that tester signals are provided to the tester pads. The membrane conductor 3 is placed on the frame 4. The fence 10 is provided on the membrane contactor 3 so as to place a semiconductor element 2 at a predetermined position of the membrane contactor 3. The fence 10 also serves to fix the semiconductor element 2 so that the semiconductor element 2 is not displaced when a shock or vibration is applied to the semiconductor element testing carrier 1.
The pressing unit 7 comprises a press plate 8 and a coil spring 9. An upper end of the coil spring 9 is engaged with the cap 5 positioned above the frame 4. The cap 5 is supported by connecting rods 6 extending from the frame 4. A lower end of the coil spring 9 is engaged with the press plate 8 so as to apply a spring force to the press plate 8. Accordingly, the pressing unit 7 presses the semiconductor element 2 toward the membrane contactor 3 via the press plate 8. Thereby, a good electric contact is achieved between the semiconductor element 2 and the membrane contactor 3.
Additionally, the frame 4 is provided with a cavity formed at a position under a position where the semiconductor element 2 is placed so that the cushion member 11 is accommodated in the cavity. The cushion member 11 contacts the membrane contactor 3 at a position opposite to the semiconductor element 2 so as to receive a pressing force applied by the pressing unit 7.
Additionally, when attaching the semiconductor element 2 to the semiconductor element testing carrier 1, first the semiconductor element 2 is placed at the predetermined position of the membrane contactor 3. At this time, the semiconductor element 2 must be precisely positioned so that the electrodes of the membrane contactor 3 are reliably connected to the electrodes of the semiconductor element 2. Thereafter, the pressing unit 7 is attached so as to press the semiconductor element 2 in a direction from the back side of the semiconductor element 2 to the membrane contactor 3. A test is performed on the semiconductor element 2 while the semiconductor element 2 is held by the semiconductor element testing carrier.
The above-mentioned conventional semiconductor element testing carrier 1 is arranged so that the pressing unit 7 is attached after the semiconductor element 2 is placed on the membrane contactor 3. Additionally, the pressing unit 7 (the press plate 8) directly contacts the semiconductor element 2. Accordingly, there is a problem in that the semiconductor element 2 is displaced relative to the membrane contactor 3 due to a shock applied by the press plate 8 to the semiconductor element 2 when the pressing unit 7 is set.
Additionally, when a shock or vibration is applied to the semiconductor element testing carrier 1 during a testing process, such a shock or vibration is directly transmitted to the semiconductor element 2. Thereby, the semiconductor element 2 may be displaced relative to the membrane contactor 3 after the assembly of the semiconductor element 2 to the semiconductor element testing carrier 1 has been completed. Thus, there is a problem in that the electrodes of the semiconductor element 2 and the membrane contactor 3 may be damaged when a displacement occurs between the semiconductor element 2 and the membrane contactor 3, which results in an incomplete electric connection.
It is a general object of the present invention to provide an improved and useful semiconductor element testing carrier in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a semiconductor element testing carrier which can prevent a semiconductor element from being displaced relative to a membrane contactor both during a testing operation and during an attaching operation of the semiconductor element to a semiconductor element testing carrier.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a semiconductor element testing carrier for holding a semiconductor element to be tested so as to obtain an electrical contact with electrodes of the semiconductor element, the semiconductor element having a first surface on which the electrodes are formed and a second surface opposite to the first surface, the semiconductor element testing carrier comprising:
a membrane contactor having a front surface and a back surface opposite to the front surface, the membrane contactor contacting the electrodes of the semiconductor element being placed on the front surface of the membrane contactor;
a pressing unit pressing the membrane contactor toward the semiconductor element from a side of the back surface of the membrane contactor;
a pressing and holding member holding the second surface of the semiconductor element; and
a contacting part protrudingly formed on one of the pressing and holding member and the membrane contactor so that the semiconductor element is held between the membrane contactor and the pressing and holding member while the membrane contactor contacts the pressing and holding member via the contacting part.
According to the above-mentioned invention, the pressing unit presses the membrane contactor from a side opposite to a side where the semiconductor element is placed. That is, the pressing unit does not directly press the semiconductor element. Additionally, the pressing and holding member holds the second surface of the semiconductor element, the second surface being opposite to the surface which contacts the membrane contactor. Further, the holding and pressing member contacts the membrane contactor via the contacting part formed on one of the pressing and holding member and the membrane contactor. Accordingly, if a shock or vibration is applied to the pressing and holding member, the semiconductor element does not move relative to the membrane contactor since the pressing and holding member is supported on membrane contactor. Additionally, since the shock or vibration applied to the pressing and holding member is transmitted to the membrane contactor via the contacting part, a damage to the semiconductor element can be reduced.
Additionally, in the semiconductor element testing carrier according to the present invention, the membrane contactor may be provided with a frame member made of a hard material, the frame member being attached to a periphery of the membrane contactor so that the frame member surrounds the pressing and holding member.
Accordingly, the periphery of the membrane contactor having a flexibility is supported by the frame member, which support facilitates handling the membrane contactor during a test process. Additionally, when a tester probe comes into contact with the membrane contactor in the test process, a reliable contact of the test probe can be achieved by the presence of the frame member which is made of a hard material.
Additionally, the semiconductor element testing carrier according to the present invention may further comprise a contactor attaching member supporting the back surface of the membrane contactor, the contactor attaching member having an opening aligning with the semiconductor element placed on the membrane contactor so that the pressing unit presses the membrane contactor through the opening.
Accordingly, the membrane contactor can be handled together with the contactor attaching member supporting. This facilitates handling the membrane contactor which alone is not easy to handle due to its flexibility.
In one embodiment, the contactor attaching member may be made of a resin, and the membrane contactor may be integrated with the contactor attaching member by insertion molding.
Additionally, in the semiconductor element testing carrier according to the present invention, a coefficient of thermal expansion of the contactor attaching member may be substantially equal to a coefficient of thermal expansion of the membrane contactor.
Accordingly, when the semiconductor element held by the semiconductor element testing carrier is subjected to a test such as a burn-in test which is performed under an increased temperature, generation of displacement or distortion between the contactor attaching member and the membrane contactor due to a difference in thermal expansion can be prevented.
In one embodiment, the pressing unit may include an elastic member generating a pressing force applied to the membrane contactor. Alternatively, the pressing unit may include a gas spring comprising a sealed compressed gas for generating a pressing force applied to the membrane contactor. The pressing unit may include a liquid spring comprising a sealed compressible liquid for generating a pressing force applied to the membrane contactor. Additionally, the pressing unit may include a vacuum apparatus for decreasing a pressure applied on the front surface of the membrane contactor. Further, the pressing unit may include a magnetic spring comprising a pair of magnets arranged so that the same poles of the magnets are opposite to each other.
Additionally, in the semiconductor element testing carrier according to the present invention, the contacting part may define a position of the semiconductor element in a plane parallel to the first surface of the semiconductor element. Accordingly, semiconductor element is securely held at a predetermined position on the membrane contactor even when a shock or vibration is applied during a test.
Additionally, the pressing and holding member may be made of a conductive material, and the membrane contactor may be provided with a grounding pad electrically connected to the pressing and holding member. Accordingly, the pressing and holding member which surrounds the semiconductor element is made of a conductive material and is grounded. Thus, the semiconductor element is shielded from external electromagnetic waves.
In one embodiment, the pressing and holding member may be provided with a cooling fin. The cooling fin can efficiently release a heat generated by the semiconductor element during a test since the pressing and holding member directly contacts the semiconductor element.
Additionally, there is provided according to another aspect of the present invention, a method for testing a semiconductor element using a semiconductor element testing carrier for holding the semiconductor element to be tested so as to obtain an electrical contact with electrodes of the semiconductor element, the semiconductor element having a first surface on which the electrodes are formed and a second surface opposite to the first surface, the semiconductor element testing carrier comprising:
a membrane contactor having a front surface and a back surface opposite to the front surface, the membrane contactor contacting the electrodes of the semiconductor element being placed on the front surface of the membrane contactor;
a pressing unit pressing the membrane contactor toward the semiconductor element from a side of the back surface of the membrane contactor;
a pressing and holding member holding the second surface of the semiconductor element; and
a contacting part protrudingly formed on one of the pressing and holding member and the membrane contactor so that the semiconductor element is held between the membrane contactor and the pressing and holding member while the membrane contactor contacts the pressing and holding member via the contacting part,
the method comprising the steps of:
placing the semiconductor element at a predetermined position on the membrane contactor;
holding the semiconductor element on the membrane contactor by attaching the pressing and holding member to the membrane contactor;
pressing the back surface of the membrane contactor toward the semiconductor element; and
testing the semiconductor element by connecting a tester to the semiconductor element testing carrier.
According to the above-mentioned invention, the pressing unit presses the membrane contactor from a side opposite to a side where the semiconductor element is placed. That is, the pressing unit does not directly press the semiconductor element. Additionally, the pressing and holding member holds the second surface of the semiconductor element, the second surface being opposite to the surface which contacts the membrane contactor. Further, the holding and pressing member contacts the membrane contactor via the contacting part formed on one of the pressing and holding member and the membrane contactor. Accordingly, if a shock or vibration is applied to the pressing and holding member, the semiconductor element does not move relative to the membrane contactor since the pressing and holding member is supported on the membrane contactor. Additionally, since the shock or vibration applied to the pressing and holding member is transmitted to the membrane contactor via the contacting part, a damage to the semiconductor element can be reduced.
Additionally, there is provided according to another aspect of the present invention a method for testing a semiconductor element using a semiconductor element testing carrier for holding the semiconductor element to be tested so as to obtain an electrical contact with electrodes of the semiconductor element, the semiconductor element having a first surface on which the electrodes are formed and a second surface opposite to the first surface, the semiconductor element testing carrier comprising:
a membrane contactor having a front surface and a back surface opposite to the front surface, the membrane contactor contacting the electrodes of the semiconductor element being placed on the front surface of the membrane contactor;
a pressing unit pressing the membrane contactor toward the semiconductor element from a side of the back surface of the membrane contactor;
a pressing and holding member holding the second surface of the semiconductor element; and
a contacting part protrudingly formed on one of the pressing and holding member and the membrane contactor so that the semiconductor element is held between the membrane contactor and the pressing and holding member while the membrane contactor contacts the pressing and holding member via the contacting part,
the method comprising the steps of:
securing the semiconductor element to the pressing and holding member;
attaching the pressing and holding member to the membrane contactor so that the semiconductor element is held at a predetermined position on the front surface of the membrane contactor;
pressing the back surface of the membrane contactor toward the semiconductor element; and
testing the semiconductor element by connecting tester to the semiconductor element testing carrier.
According to this invention, since the pressing and holding member is attached to the membrane contactor after the semiconductor element is secured to the pressing and holding member, the semiconductor element does not move after the semiconductor element is positioned at the predetermined position and until the pressing unit is attached.
Additionally, there is provided according to another aspect of the present invention a semiconductor element testing apparatus comprising:
a semiconductor element testing carrier for holding a semiconductor element to be tested so as to obtain an electrical contact with electrodes of the semiconductor element, the semiconductor element having a first surface on which the electrodes are formed and a second surface opposite to the first surface, the semiconductor element testing carrier comprising:
a membrane contactor having a front surface and a back surface opposite to the front surface, the membrane contactor contacting the electrodes of the semiconductor element being placed on the front surface of the membrane contactor;
a pressing unit pressing the membrane contactor toward the semiconductor element from a side of the back surface of the membrane contactor;
a pressing and holding member holding the second surface of the semiconductor element; and
a contacting part protrudingly formed on one of the pressing and holding member and the membrane contactor so that the semiconductor element is held between the membrane contactor and the pressing and holding member while the membrane contactor contacts the pressing and holding member via the contacting part;
a base supporting the membrane contactor, the base having an opening located under the membrane contactor when the contactor is placed on the base, the opening aligning with the pressing unit located under the base; and
a conveyance robot provided with the pressing and holding member so as to move the semiconductor element between the predetermined position on the front surface of the membrane contactor and a tray for storing the semiconductor element, the robot holding the pressing and holding member on the membrane contactor so as to test the semiconductor element.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.